Balanced LED backlighting for liquid crystal display (LCD)

ABSTRACT

Techniques for providing LED-based backlighting in liquid crystal flat panel displays are disclosed. In one embodiment, optical sensors are provided to sense illuminations from colored LED groups and provide feedback signals to a controller so that a desired ratio of the illuminations is maintained. As a result, true colors could be reproduced regardless of possible irregularities that may be happening to LEDs used in the colored LED groups to backlight an LCD panel.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. application Ser. No. 13/183,429 filed onJul. 15, 2011 now U.S. Pat. No. 8,188,957, which is a continuation ofU.S. application Ser. No. 11/065,699 filed on Feb. 23, 2005, now U.S.Pat. No. 7,990,352 issued on Aug. 2, 2011.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to the area of display devices. Moreparticularly, the present invention is related to techniques of using aliquid crystal display without subpixels or color filters to displaycolors from colored backlighting.

2. Description of the Related Art

Liquid crystal display (LCD) is one of the popular display devices forconveying digital information, such as images, data and movies. Thedecreased weight and size of a flat panel display greatly increases itsversatility over a cathode ray tube (CRT) display. High quality flatpanel displays are typically back-lit. That is, a source of illuminationis placed behind the LCD layers to facilitate visualization of theresultant image. Flat panel LCD devices or units are used today in manyapplications including the computer industry where flat panel LCD unitsare an excellent display choice for lap-top computers and other portableelectronic devices. Because the technology of flat panel LCD units isimproving, they are being used more and more in other mainstreamapplications, such as desktop computers, high-end graphics computers,and as television and other multi-media monitors.

Most computer LCD panels are back-lit with built-in fluorescent tubesbehind the LCD. A white diffusion panel behind the LCD redirects andscatters the light evenly to ensure a uniform display. This is known asa backlight or backlighting. One of the commonly used fluorescent tubesin LCD panels is a tiny Cold Cathode Fluorescent Lamp (CCFL) for thebacklight. It provides a bright white light source that can be diffusedby the panel behind the LCD. In addition to providing ample lighting,CCFLs do not rise far above the ambient temperature. This makes themideal for LCD panels since the light source is in close proximity toother components that could be ruined by excessive heat.

One amazing thing about these CCFLs is their incredible size. They arevery thin and the board that drives a lamp is very small as well.However, it is not that hard to break them, which is why the LCD displaymay go dark if a laptop computer drops onto a hard floor but stillworks.

While everyone appears to be focused on the “zero radiation” advantageof the LCD technology, no one actually think what is behind the liquidcrystals (which the “L” and “C” letters stand for). This happened to bethe same fluorescent light technology which was not recommended for useas the only light source in offices.

A fluorescent light is most often a long straight glass tube thatproduces white light. Inside the glass tube there is a low-pressuremercury vapor. When ionized, mercury vapor emits ultraviolet light.Human eyes are not sensitive to ultraviolet light. The inside of afluorescent light is coated with phosphor. Phosphor is a substance thatcan accept energy in one form and emit the energy in the form of visiblelight. For example, energy from a high-speed electron in a commonly seenTV tube, also referred to as cathode ray tube or CRT, is absorbed by thephosphors that make up the pixels. The light from a fluorescent tube isthe light given off by the phosphor coating the inside of the tube. Thephosphor fluoresces when energized, hence the name. It has beenconcluded that directly staring at a source of fluorescent light can bejust as bad, if not worse. But there is no mentioning anywhere that thatmost LCD panels are actually a reflection of fluorescent lights and inmany cases people spend a considerable amount of time in a day staringat such a source.

Another one of the reasons that a fluorescent light is used as abacklighting source is the inherent characteristics of being close tothe sunlight. However, the spectrum of a typical fluorescent light is noclose to that of the sunlight, often requiring compensation on whitebalance. No or improper adjustments on white balance would result indistortions of colors.

U.S. Pat. No. 6,657,607 proposes a solution of using multiple lightsources for color balancing within a liquid crystal flat panel displayunit. In particular, altering the brightness of two or more lightsources, having differing color temperatures, is thus providing colorbalancing of a liquid crystal display unit within a given colortemperature range. The patent, however, corrects only one aspect of theproblems in a liquid crystal display that is backlit by fluorescentlighting by introducing additional lighting sources and polarizationmeans.

Light emitting diodes provide an alternative light source to thefluorescent light source. Besides having a much longer operating life,the light emitting diodes provide steady and pure colors. The currentapplications of the light emitting diodes in LCD are largely to combinethe colored lights from the light emitting diodes for a simulated whitelight. The inventors herein have conceived that the light emittingdiodes as the backlighting, if designed properly, can be used to enhancemany properties of LCD.

SUMMARY OF THE INVENTION

This section is for the purpose of summarizing some aspects of thepresent invention and to briefly introduce some preferred embodiments.Simplifications or omissions in this section as well as in the abstractand the title may be made to avoid obscuring the purpose of thissection, the abstract and the title. Such simplifications or omissionsare not intended to limit the scope of the present invention

The invention pertains to liquid crystal display (LCD) that inherentlyhas no suppixels and no color filters but is capable of displayingcolors, hence referring to as monochromic LCD. In a traditional LCDpanel for colors, each pixel includes three subpixels that act threerespective light passage of three colored lights, such as red, green andblue. By controlling the three subpixels as well as the amount of lightpassing through each of the three pixels, millions of colors could beperceived. However, one of the problems in the traditional LCD panel isthe loss of display resolution. According to one aspect of the presentinvention, each pixel in an LCD does not have any subpixels and colorfilters, and works independently, hence the display resolution isgreatly enhanced without actually increasing additional pixels.

According to another aspect of the present invention, unlike thesubpixels in the traditional LCD in that each of the subpixels ispredetermined to pass a specified colored light, such as three subpixelsin a pixel are configured to transmit respectively red, green and bluelights, each of the pixels in the LCD contemplated in the presentinvention is not configured to pass a predefined colored light. In oneembodiment, three colored lights are turned on successively, dependingon an image to be displayed, all pixel are respectively controlled toallow no, all or some of one or more of the three colored lights topass, resulting in millions of perceived colors.

According to still another aspect of the present invention, the lightemitting diodes are in more than three predetermined colors but stillgrouped as three color lights groups or simply group herein. One of thepurposes of having more than one colored lights in a color group is toensure that the visible spectrum is as much covered as possible.

The present invention may be implemented as a method, an apparatus or aport of a system. According to one embodiment, a liquid crystal displaydevice comprising a liquid crystal display panel including a pluralityof pixels, each of the pixels including no further subpixels andreproducing a perceived color from one or more colored lights that aretransmitted successively through a corresponding liquid crystal turnedon in accordance with a display signal that is supposed to be displayedon the liquid crystal display panel, wherein the display signal mayinclude, but may not be limited to, a text signal, an image signal or avideo signal.

The foregoing and other objects, features and advantages of theinvention will become more apparent from the following detaileddescription of a preferred embodiment, which proceeds with reference tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings,wherein like reference numerals designate like structural elements, andin which:

FIG. 1A shows an array of pixels in a traditional LCD, each of thepixels has three subpixels respectively for transmit a red, a green anda blue light;

FIG. 1B shows a cross sectional view of an LCD device that employs theLCD of FIG. 1A;

FIG. 2A shows an exemplary LCD device contemplated in the presentinvention;

FIG. 2B shows an exemplary embodiment of an LCD that may be used in FIG.2A;

FIG. 2C shows operations of controlling pixels in the LCD of FIG. 2Bwith colored backlighting to reproduce colors;

FIG. 3A shows three respective spectrums of three color (e.g., red,green and blue) groups of light emitting diodes superimposed by threeapproximated spectrums of red, green and blue that can be primarilyperceived by a human vision system; and

FIG. 3B shows that three types of light emitting diodes with similarcolor bins are used as a first color group, two types of light emittingdiodes with similar color bins are used as a second color group, andanother three types of light emitting diodes with similar color bins areused as a third color group.

DETAILED DESCRIPTION OF THE INVENTION

The invention pertains to liquid crystal display (LCD) that inherentlyhas no suppixels and no color filters but is capable of displayingcolors. According to one aspect of the present invention, each pixel inan LCD does not have any subpixels, as if each of the subpixels is apixel, hence the display resolution of the LCD is greatly enhancedwithout actually increasing additional pixels. According to anotheraspect of the present invention, unlike the subpixels in the traditionalLCD in that each of the subpixels is predetermined to pass a specifiedcolored light, such as three subpixels in a pixel are configured totransmit respectively red, green and blue lights, each of the pixels inthe LCD contemplated in the present invention is not configured to passa predefined colored light. In one embodiment, three colored lights areturned on successively, depending on an image to be displayed, all pixelare respectively controlled to allow no, all or some of one or more ofthe three colored lights to pass, resulting in millions of perceivedcolors.

The detailed description of the invention is presented largely in termsof procedures, steps, logic blocks, processing, and other symbolicrepresentations that directly or indirectly resemble the operations ofdata processing devices coupled to networks. These process descriptionsand representations are typically used by those skilled in the art tomost effectively convey the substance of their work to others skilled inthe art. Reference herein to “one embodiment” or “an embodiment” meansthat a particular feature, structure, or characteristic described inconnection with the embodiment can be included in at least oneembodiment of the invention. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment, nor are separate or alternativeembodiments mutually exclusive of other embodiments. Further, the orderof blocks in process flowcharts or diagrams representing one or moreembodiments of the invention do not inherently indicate any particularorder nor imply any limitations in the invention.

It deems necessary to review some basics of a liquid crystal display(LCD). As the name suggests, one of the main materials in an LCD isliquid crystals while one of the features of the liquid crystals is thatthey are affected by an electrical field applied thereon. A particularsort of nematic liquid crystal used in an LCD, called twisted nematics,is naturally twisted. Applying an electrical field to these liquidcrystals will untwist them to varying degrees, depending on the amountof the current. An LCD operates based on these liquid crystals becausethey react predictably to an electrical field in such a way as tocontrol light passage.

There are two main types of LCD used in display devices, passive matrixand active matrix. Passive-matrix LCD uses a simple grid to supply acharge to a particular pixel on the display. The process starts with twoglass layers called substrates. One substrate is given columns and theother is given rows made from a transparent conductive material. This isusually indium-tin oxide. The rows or columns are connected to a circuitthat controls when a charge is sent down a particular column or row. Theliquid crystal material is sandwiched between the two glass substrates,and a polarizing film is added to the outer side of each substrate. Toturn on a pixel, the circuit sends a charge down the correct column ofone substrate and a ground activated on the correct row of the other.The row and column intersect at the designated pixel, and that deliversthe voltage to untwist the liquid crystals at that pixel.

Active-matrix LCD depends on thin film transistors (TFT). Basically,TFTs are tiny switching transistors and capacitors. They are arranged ina matrix on a glass substrate. To address a particular pixel, the properrow is switched on, and then a charge is sent down the correct column.Since all of the other rows that the column intersects are turned off,only the capacitor at the designated pixel receives a charge. Thecapacitor is able to hold the charge until a next refresh cycle. And ifthe amount of voltage supplied to a crystal is carefully controlled, thecrystal can be untwisted just enough to allow some light through. Bydoing this in very exact, very small increments, an LCD can create agray scale provided there is a white backlighting. Most displays todayoffer 256 levels of brightness per pixel. An LCD that can show colorsmust have three subpixels with red, green and blue color filters tocreate each color pixel.

FIG. 1A shows an array of pixels 120 in an LCD. Each of the pixels, suchas a pixel 122, has three subpixels labeled respectively red, green andblue. Through the careful control and variation of the voltage appliedwhile each subpixel can reach 256 levels of brightness (shades) perpixel. Combining the subpixels produces a possible palette of 16.8million colors (e.g., 256 shades of red×256 shades of green×256 shadesof blue). For example, when two subpixels in pixels 124 and 126 areapplied with control signals via column and row lines, the backlightingpasses through the red and green subpixels, causing a mixed impressionof “yellow”. In extreme cases, when all subpixels in a pixel are turnedon or off, a white or black color is created or perceived. Inapplications of showing an image or video on an LCD, control signals inaccordance with an image or video are applied to the pixels,respectively, causing the subpixels in each of the pixels respectivelyon or off. As a result, the image or video is displayed on the LCD.

Referring now to FIG. 1B, there shows a cross sectional view of an LCDdevice 100 that employs an LCD 102 that may be the LCD 120 of FIG. 1A.The LCD device 100 includes the LCD 102 and a backlighting section 104.Depending on manufacturing process or specification configuration, theLCD 102 comprises at least some of a protective layer, a polarizationlayer, a front layer, a color filter layer, an LCD layer, a back glasslayer and a polarizer layer. The backlighting section 104 typicallyincludes a light source producing white lighting. Commonly, the lightsource may be one or more of cold cathode fluorescent lamps or an arrayof light emitting diodes. Through the selective color filtering by thesubpixels in the LCD 102, an color image or video can be displayed.

One of the problems, however, in the LCD 120 or the LCD device 100 isthe loss of display resolutions. As shown in FIG. 1A, every threesubpixels are used only as a single pixel. For example, a typical laptopcomputer supports display resolutions up to 1,024×768. Themultiplication of 1,024 columns by 768 rows by 3 subpixels is 2,359,296,which means that there are an enormous number of transistors that haveto be etched on a substrate in the LCD 120. If the resolutions arehigher (e.g., in LCD TV), the number of transistors that have to beetched on a substrate would be increased enormously, so does the cost ofthe LCD.

Another one of the problems in the LCD 120 is the tailing effects oftenseen in a video with fast moving objects. Because the “on” and “off”status (refreshing) of the subpixels are controlled periodically, whenthe objects in a scene move too fast (e.g., faster than the refreshingspeed), tailing effects would be shown, causing blurred display of theobjects. To reduce such artifacts, there have been many effortsincluding increasing the refreshing speed. But in the end, the costs ofproducing an LCD are often increased accordingly.

FIG. 2A shows an LCD device 200 contemplated in the present invention.The LCD device 200 includes an LCD 202 that is further shown in FIG. 2B.Different from the LCD 120 of FIG. 1A, the LCD 202 does not have theconcept of subpixels. The LCD 202 is essentially monochromic. When apixel includes three subpixels, the resultant display resolutions of anLCD are significantly reduced because three subpixels work as a singlepixel. For example, for a display image resolution of 1,024 columns by768 rows, the LCD 120 of FIG. 1A has to have 2,359,296 subpixels intotal. As described below, the LCD 202 needs only 1,024×768=786,432pixels. If each subpixel was used as an independent pixel, with2,359,296 subpixels, the LCD 202 would be able to provide a much higherdisplay resolution.

Since no subpixels are used, each pixel in the LCD 202 is configuredindependently to provide a light path in a controlled manner, namely,only a specified amount of light can be passed through a pixel. In oneembodiment, with proper electrical field (via voltage/current) appliedthereto, 256 levels of light amount can be passed through a pixel in acontrolled manner. Such 256 levels are equivalent to 256 levels oflightness (grey levels) that may be provided by the LCD 202. One of thefeatures in the present invention is to have the LCD 202 to reproducecolors. The colors are in fact provided by the backlighting that uses atleast three colored light sources.

Behind the LCD 202 is an LED based backlight section that includes agroup of diffuser(s) and reflector(s) 204 and an array or matrix oflight-emitting diodes 206. The diffuser(s) and reflector(s) 204,together with other optical parts (not shown, e.g., reflectors), provideoptical means to distribute lighting from the light-emitting diodes 206evenly to LCD 202. In the embodiment shown in FIG. 2A, thelight-emitting diodes 206 comprise at least three types of coloredlight-emitting diodes. In one embodiment, three colored light-emittingdiodes, such as Red, Green and Blue, are used.

To ensure that a white color is balanced or at a desired colortemperature, a controller 208 is provided to control the power supply210 that drives the light-emitting diodes 206. The controller 208receives at least three types control signals, sensor feedback signals212, video control signals 214 and lighting control signals 216.

In one embodiment, the sensor feedback signals 212 are from sensorspositioned to sense the resultant backlighting. For three types ofcolored light-emitting diodes in red, green and blue, three sensors 209are provided to sense respectively the red, green and blue lighting andprovide respective feedback signals to the controller 208. For example,it is desired to have a relative power ratio of three coloredlight-emitting diodes as R:G:B=0.9:1:08. For some reasons, the ratio isno longer holding, the three sensors 209 can immediately detect thedifference and send the feedback signals to the controller 208 thatdetermines what necessary adjustments need to be provided to the powersupply 210 that in return causes the colored light-emitting diodes tokeep the ratio. In another embodiment, there are more than three sensorsfor more types of light-emitting diodes. Optionally, one of the sensorsis provided to sense brightness of the combined lighting provided by thelight-emitting diodes. In case, the overall brightness exceeds a certainthreshold, the brightness sensor can detect and reduce the powerproportionally to drive the light-emitting diodes. Further, othersensors may be used to sense individual color brightness and/orwavelength of each of the types of light emitting diodes or control theduty cycles of the light-emitting diodes to achieve desired backlightingfor certain applications.

The video control signals 214 are a type of signals derived from a videoprocessor configured to process display (video or image) signals fordisplay on the LCD device. In the traditional display approach, thedisplay signals are provided directly to the LCD 202 to control “on” or“off” of the subpixels, or precisely, control respective liquid crystalsto allow a certain amount of white light to pass through correspondingcolor filters, resulting in color reproductions. In the presentinvention, the video control signals 214 are derived from the videosignals to control respective liquid crystals to allow a certain amountof colored light to pass through for a controlled period, relying on theinherent color combining capability in human visual system to perceive aresultant combined color.

FIG. 2C shows operations of controlling pixels in the LCD 202 withcolored backlighting to reproduce colors. It is assumed that row r3 andcolumn c5, c6 and c7 are selected via one or more LCD drivers 217. As aresult, there are three pixels that are activated for display. In oneembodiment, the colored backlighting employs red, green and blue LEDsthat are turned successively in time. In accordance with a displaysignal 214 from the video processor 218, it is assumed that these pixelsneed to display “yellow”, “orange” and “grey” sequentially at t1, t2 andt3. One of the important features in the present invention is to controlthe respective liquid crystals in these pixels to let proper coloredlights to pass through so that the desired colors “yellow”, “orange” and“white” are displayed or perceived at the right times.

During t1, the crystals of these pixels are fully turned to allow fullpassage of two colored lights for a predefined period and completelyblock the third one, in which both red and green lighting aresuccessively passed through and blue lighting is blocked. When a viewersees a red and a green light coming out successively in time and fastenough, the perceived color is “yellow” in human vision, wherein a“yellow” color is a combination of these two primary colors.

During t2, the crystals of these pixels are fully turned to allow fullpassage of a first colored light, half turned to allow half passage of asecond colored light and block a third colored light. In the firstpredefined period with the full passage, only red light is fully passedthrough. In the second predefined period with the half passage, only 50%of the green light is passed through, resulting in a perceived “orange”in human vision.

During t3, the crystals of these pixels are half turned to allow halfpassage of all three colored lights to pass through, namely red, green,and blue colored lights, resulting in a perceived “gray” color in humanvision. It can be understood that when the crystals of these pixels arefully turned to allow full passage of all three colored lights to passthrough, the perceived color in human vision will be white.

In one embodiment, the passage of light by the crystals can becontrolled to 256 different levels (shades). With the three coloredlights, there can be 16.8 million different colors that can beperceived. Accordingly, as shown in FIG. 2C, the corresponding outputfor the color is (R, G, B)=(255, 255, 0) during t1, the correspondingoutput for the color is (R, G, B)=(255, 128, 0) during t2, and thecorresponding output for the color is (R, G, B)=(255, 255, 255) duringt3.

Referring back to FIG. 2A, the lighting control signals 216 aregenerated in accordance with a desired setting. For example, a certainTV manufacturer prefers to make some of its LCD TV sets to be a littlereddish and others to be a little bluish. Accordingly, a 6500 K whitecolor temperature (slightly reddish) or a 9000K white color temperature(slightly bluish) can be produced with proper weights on the respectivelight-emitting diodes. In one embodiment, three types of colored lightemitting diodes are used, the relative power ratio of three coloredlight emitting diodes as R:G:B=1:1:0.9 is used. The correspondinglighting control signals 216 are thus generated to be sent to thecontroller 208 that ensures the power supply 210 to control the threecolored light-emitting diodes in accordance with the ratio. Depending onimplementation, other control signals, such as a brightness controlsignal, may be included in the lighting control signals 216.

With the sensor feedback signals 212, the video control signal 214 andthe lighting control signals 216, the backlighting in a LCD device canbe provided in any desirable way and readily controlled. In oneembodiment, the light emitting diodes are in three colored groups, eachcolored group produces a desired color corresponding to a colortemperature in the CIE colorimetry system. The optical sensors 209 areprovided to ensure that such color temperature is maintained byproviding the sensor feedback signals 212 to controller 208.

In LCD applications, colors are reproduced by combining three primarycolors (e.g., red, green and blue). FIG. 3A illustrates three respectivespectrums 320, 322, and 324 of three color (red, green and blue) groupsof light emitting diodes. Superimposed are three approximated spectrums326, 328, and 330 of red, green and blue that can be primarily perceivedby a human vision system. Any colors mixed by red, green and blue can beperceived. However, the spectrums 320, 322, and 324 are much narrowerthan the spectrums 326, 328, and 330, there are certain colors thatwould not be reproduced because certain wavelengths are not there or notstrong enough to reproduce the colors (e.g., colors around 500 nm or 600nm).

An advantage of light-emitting diodes is that they are available inalmost any wavelength in the visible region. For categorization, thelight emitting diodes come in color bins or groups, each bin or groupconcentrating on a color. As used herein, a color of a light emittingdiode means one of the color bins or groups. With the flexibilities ofthe colors of the light emitting diodes, the spectrum design of aprimary color (e.g., red, green or blue) or even a white color (whitebalance) by the light-emitting diodes may be more flexible than fortraditional discharge lamps. In one embodiment, more than three types oflight-emitting diodes are used. FIG. 3B shows that three types of lightemitting diodes with similar color bins 332 are used as a first colorgroup, two types of light emitting diodes with similar color bins 334are used as a second color group, and three types of light emittingdiodes with similar color bins 336 are used as a third color group. As aresult, nearly all colors can be reproduced by various mixtures of thethree color groups.

Without loss of generality, the above embodiment may be described in thefollowing. It is assumed a backlighting group C to reproduce all colorsdefined by a desired triangle, a spectrum or the entire CIE chromaticitydiagram includes a set or group of R(i), G(i), and B(i), eachrepresenting one color group of light emitting diode, where i=1, 2, . .. , N, thus:

$C = \left\{ {{\sum\limits_{i = 1}^{N}{R\left( {\lambda\; i} \right)}},{\sum\limits_{i = 1}^{M}{G\left( {\lambda\; i} \right)}},{\sum\limits_{i = 1}^{K}{B\left( {\lambda\; i} \right)}}} \right\}$where N, M and K are integers and may or may not be identical, λindicates a wavelength or a color. When a backlighting section employs aplurality of sets of the backlighting groups, an even and full colorspectrum of backlighting can be achieved, resulting in vivid displays ofall desired colors. In addition, the full color spectrum can be broaderthan the color spectrum defined by a TV standard such as NTSC or PAL.

The invention may be implemented as a method, an apparatus or a port ofa system, each yielding one or more of the following advantages and/orbenefits. First, each pixel in an LCD does not have any subpixels, as ifeach of the subpixels in the traditional LCD is an independent pixel,hence the display resolution is greatly enhanced without actuallyincreasing additional pixels. Secondly, unlike the subpixels in thetraditional LCD in that each of the subpixels is predetermined to pass aspecified colored light, such as three subpixels in a pixel areconfigured to transmit respectively red, green and blue lights, each ofthe pixels in the LCD contemplated in the present invention is notconfigured to pass a predefined colored light, the cost and complexityof the LCD are greatly reduced. Third, unlike the traditional LCD thatuses subpixels in parallel, each for a color, the monochromic LCD asused herein has all colored lights come from a same pixel, thus colorsare substantially registered, thus minimizing the possibility of colormosaic. Fourth, the light emitting diodes are in more than threepredetermined colors but still grouped as three color lights. One of thepurposes of having more than one colored lights in a color group is toensure that the visible spectrum is as much covered as possible. Otheradvantages or benefits are apparent to those skilled in the art from thedescription herein.

The present invention has been described in sufficient detail with acertain degree of particularity. It is understood to those skilled inthe art that the present disclosure of embodiments has been made by wayof examples only and that numerous changes in the arrangement andcombination of parts may be resorted without departing from the spiritand scope of the invention as claimed. While the embodiments discussedherein may appear to include some limitations as to the presentation ofthe information units, in terms of the format and arrangement, theinvention has applicability well beyond such embodiment, which can beappreciated by those skilled in the art. Accordingly, the scope of thepresent invention is defined by the appended claims rather than theforegoing description of embodiments.

1. A liquid crystal display (LCD) device comprising: a backlighting unitcomprising a first light source of a first color, a second light sourceof a second color, and a third light source of a third color, thebacklighting unit configured to illuminate, in a cycle, the first lightsource during a first time in the cycle, the second light source duringa second time in the cycle, and the third light source during a thirdtime in the cycle; a liquid crystal display panel comprising a pluralityof pixels, wherein ones of the plurality of pixels are configured topermit passage of a percentage of light of the first color during thefirst time in the cycle, a percentage of light of the second colorduring the second time in the cycle, and a percentage of light of thethird color during the third time in the cycle; at least one firstoptical sensor configured to sense at least one characteristic of eachof the respective illuminations of the first color, the second color,and the third color; at least one second optical sensor configured tosense at least one characteristic of the combined light fromilluminations of the first color, the second color, and the third color;and a controller configured to receive feedback signals from the atleast one first optical sensor and the at least one second opticalsensor, the controller configured to control the first light source, thesecond light source, and the third light source based on the feedbacksignals.
 2. The LCD device of claim 1, wherein the controller is furtherconfigured to control the first light source, the second light source,and the third light source in accordance with a display signal to bedisplayed on the LCD device.
 3. The LCD device of claim 2, wherein thedisplay signal is an image or a video.
 4. The LCD device of claim 3,further comprising one or more drivers to control the plurality ofpixels in the liquid crystal display panel in accordance with thedisplay signal.
 5. The LCD device of claim 2, further comprising one ormore drivers to control the plurality of pixels such that an amount oflight passing through the liquid crystal plurality of pixels iscontrolled in accordance with the display signal.
 6. The LCD device ofclaim 1, further comprising one or more drivers to control the pluralityof pixels such that the percentage of light of the first color duringthe first time in the cycle, the percentage of light of the second colorduring the second time in the cycle, and the percentage of light of thethird color during the third time in the cycle produce a desired colorduring the cycle.
 7. The LCD device of claim 1, wherein the first coloris red, the second color is green, and the third color is blue.
 8. TheLCD device of claim 1, wherein illumination of the first light source,the second light source, and the third light source includes offsets inwavelengths or colors.
 9. The LCD device of claim 8, wherein the offsetsin wavelengths or colors permit colors in a predefined visible spectrumto be substantially reproduced.
 10. The LCD device of claim 9, whereinthe predefined visible spectrum comprises colors defined in accordancewith a TV standard.
 11. A liquid crystal display (LCD) devicecomprising: a backlighting unit including three colored groups of atleast one light source that are illuminated successively in a cycle;three sensors configured to sense illuminations from each of the threecolored groups of at least one light source; at least one sensorconfigured to sense illuminations of all of the three colored groups ofat least one light source over at least one cycle; a controller,configured to receive control signals from the three sensors and the atleast one sensor and further configured to control the three coloredgroups of at least one light source to keep a desired ratio of theilluminations from the three colored groups of at least one lightsource; and a liquid crystal display panel including a plurality ofpixels, wherein ones of the plurality of pixels are configured to permitpassage of an amount of light illuminated from each of the three coloredgroups of at least one light source.
 12. The LCD device of claim 11,further comprising one or more drivers configured to control theplurality of pixels in the liquid crystal display panel in accordancewith a display signal.
 13. The LCD device of claim 11, furthercomprising one or more drivers configured to control the plurality ofpixels such that the amount of light passing through the ones of theplurality of pixels is controlled in accordance with the display signal.14. The LCD device of claim 11, further comprising one or more driversconfigured to control a duration that the ones of the plurality ofpixels allow light illuminated from the three colored groups of at leastone light source to pass in accordance with the display signal.
 15. Amethod for use with a liquid crystal display device, comprising:illuminating light through a plurality of pixels in the liquid crystaldisplay device in a cycle, the illuminating comprising: illuminating afirst light source of a first color during a first time in the cycle andpermitting passage of an amount of the illuminated light of the firstcolor through ones of the plurality of pixels, illuminating a secondlight source of a second color during a second time in the cycle andpermitting passage of an amount of the illuminated light of the secondcolor through ones of the plurality of pixels, and illuminating a thirdlight source of a third color during a third time in the cycle andpermitting passage of an amount of the illuminated light of the thirdcolor through ones of the plurality of pixels; sensing, by at least onefirst optical sensor, at least one characteristic of each of therespective illuminations of the first color, the second color, and thethird color; sensing, by at least one second optical sensor, at leastone characteristic of the combined light from illuminations of the firstcolor, the second color, and the third color; and controlling theillumination of each of the first light source, the second light source,and the third light source based on feedback signals generated by the atleast one first optical sensor and the at least one second opticalsensor.
 16. The method of claim 15, further comprising: controlling thefirst light source, the second light source, and the third light sourcein accordance with a display signal.
 17. The method of claim 16, whereinthe display signal is representative of an image or a video.
 18. Themethod of claim 16, further comprising: controlling the plurality ofpixels in accordance with the display signal.
 19. The method of claim18, wherein the plurality of pixels is controlled to permit passage ofamounts of the illuminated light of the first color, the second color,and the third color in accordance with the display signal.
 20. Themethod of claim 15, further comprising: controlling the amounts of theilluminated light of the first color, the second color, and the thirdcolor permitted to pass through the plurality of pixels during thefirst, second, and third times in the cycle to produce a desired colorduring the cycle.